The answer is C.15, USSR broke into 15 republics including Russia itself.
A cyclic change in the earth system repeats the same steps over and over, though not necessarily with the same results or at the same rate.
The Earth's climate cycles across a wide range of time scales, from years to decades to centuries to millennia. Different physical processes can start cycles at different scales. All of these layered systems and cycles working in concert determine the climate over any particular period.
Scientists examine Earth's cycles in an effort to understand how our world functions. Our planet's climates can vary as a result of modifications to Earth's cycles. Our understanding of how humans are influencing these cycles and how that can transform the world will grow as we learn more about them.
To learn more about cyclic change of earth here
brainly.com/question/15325458
#SPJ4
